Current State of Global African Swine Fever Vaccine Development under the Prevalence and Transmission of ASF in China

Keke Wu,Lin Yi,Mingqiu Zhao,Jinding Chen,Jiameng Liu,Zhaoyao Li,Shuangqi Fan,Yuwan Li,Lianxiang Wang,Hongxing Ding

doi:10.3390/vaccines8030531

Abstract

African swine fever (ASF) is a highly lethal contagious disease of swine caused by African swine fever virus (ASFV). At present, it is listed as a notifiable disease reported to the World Organization for Animal Health (OIE) and a class one animal disease ruled by Chinese government. ASF has brought significant economic losses to the pig industry since its outbreak in China in August 2018. In this review, we recapitulated the epidemic situation of ASF in China as of July 2020 and analyzed the influencing factors during its transmission. Since the situation facing the prevention, control, and eradication of ASF in China is not optimistic, safe and effective vaccines are urgently needed. In light of the continuous development of ASF vaccines in the world, the current scenarios and evolving trends of ASF vaccines are emphatically analyzed in the latter part of the review. The latest research outcomes showed that attempts on ASF gene-deleted vaccines and virus-vectored vaccines have proven to provide complete homologous protection with promising efficacy. Moreover, gaps and future research directions of ASF vaccine are also discussed.

Highlights

African swine fever (ASF) is a highly contagious animal infectious disease caused by African swine fever virus (ASFV) infecting both wild (Sus scrofa) and domestic swine of all breeds and ages.ASF with the acute form has a rapid onset and a short course of disease, which are characterized by high fever, loss of appetite, cyanosis, severe bleeding of internal organs and a high mortality rate of nearly 100% [1,2]
Zhou et al [13] found that ASFV-SY18, the first outbreak strain diagnosed in China, belonged to the genotype II group and shared 100% nucleotide identity with the strains isolated in Georgia, Russia, and Estonia based on the p72 gene fragment, which indicated the close relationship among these viruses
The results clearly demonstrate that the adjuvant effect of swine leukocyte antigen II (SLA-II), which could enhance the immune response induced in pigs, and confirmed the critical role of CD8+ T cells in the response to ASFV [92]

Summary

Introduction

African swine fever (ASF) is a highly contagious animal infectious disease caused by African swine fever virus (ASFV) infecting both wild (Sus scrofa) and domestic swine of all breeds and ages.ASF with the acute form has a rapid onset and a short course of disease, which are characterized by high fever, loss of appetite, cyanosis, severe bleeding of internal organs and a high mortality rate of nearly 100% [1,2]. African swine fever (ASF) is a highly contagious animal infectious disease caused by African swine fever virus (ASFV) infecting both wild (Sus scrofa) and domestic swine of all breeds and ages. Arbovirus whose genome is double-stranded DNA, ASFV genome shows significant variations in length from 170 to 194 kb, which mainly results from gain or loss of different members of multigene families (MGF) [3], and encodes 150–167 proteins including structural and host immunomodulatory proteins [4,5]. Introduced breeding pigs must be isolated for more than 30 days and tested clinically and laboratory to ensure that ASFV was negative. Strict disinfection treatment of items entering pig farms by fumigation, ozone and other methods. Personnel inside the pig farm should reduce their outgoing activities and isolation measures for admission personnel should be implement strictly

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